Feed device and feed method for a pyrolysis apparatus

ABSTRACT

A feed device of a pyrolysis apparatus and a feed method through which material processed in the pyrolysis apparatus, such as plastic and/or rubber waste, can be fed into the pyrolysis apparatus. In the feed device there is a feed opening for the material to be processed, a feed chamber, closing members in conjunction with the feed chamber and a discharge opening, through which the material to be processed can be conveyed to the pyrolysis apparatus&#39;s pyrolysis chamber. A vacuum pump has been adjoined in conjunction with the feed device&#39;s feed chamber to achieve a vacuum or sufficient underpressure in the feed chamber after the material to be processed has been fed into the feed chamber and the feed chamber&#39;s closing members have been closed. After the closing member of the feed chamber&#39;s discharge opening has been opened, the material to be processed, from which the oxygen harmful to the pyrolysis process has been removed, is conveyed into the pyrolysis chamber.’

The object of the invention is a pyrolysis apparatus feed device andpyrolysis apparatus feed method according to the preamble to claim 1.

A pyrolysis apparatus is used for processing shredded waste material,such as plastic and/or rubber waste using pyrolysis. Pyrolysis, i.e. drydistillation, is a chemical reaction wherein organic solids aredecomposed by heating without allowing oxygen to influence the process.Pyrolysis usually uses either a vacuum, as is the case in vacuumpyrolysis, or an inert atmosphere, such as nitrogen, to supplantatmospheric oxygen. As a general rule, industrial pyrolysis reactionstake place at temperatures of 300 to 700° C. Known pyrolysis apparatuseshave been presented in the publications DE102013003319 A1, U.S. Pat. No.2,033,730 and US2007029184 A1.

In the pyrolysis apparatus, waste that contains hydrocarbons, forexample plastic and/or rubber waste, is processed such that the processmainly produces oil, carbon and gas. According to a known method,plastic and/or rubber waste is shredded and the shredded material isplaced in a pyrolysis chamber. The chamber is locked to make itair-tight with an air trap which is usually also the closing device forthe feed opening for the material to be processed. This allows the feedmaterial to be first fed into the feed chamber, which is equipped withclosing members such as hatches or valves. When the material has beenfed into the closed chamber, the feed hatch is closed. Then the hatch orvalve leading to the reactor chamber is opened. This prevents outsideair from freely entering the reactor chamber. In known pyrolysisapparatuses, however, air entering the closed chamber enters the reactorchamber along with the material fed into it, wherein the oxygen itcontains can disrupt the reactor's production process. It is importantin pyrolysis reactions that oxygen does not enter the reactor to inducecombustion in the reactor because the carbon dioxide resulting from thecombustion reduces the quality of the end product.

Pyrolysis apparatuses also use feed devices which have a scraperconveyor or a screw conveyor in an inclined position, whose bottom partis placed in a liquid, such as oil, contained in a liquid basin. Therebythe liquid forms an air trap to prevent air from entering into thereactor. The material to be fed into the pyrolysis apparatus is conveyedinto a bin which simultaneously forms a liquid basin. The scraperconveyor placed in an inclined position lifts the material out of theliquid contained in the bin. From the top end of the scraper conveyor,the material falls into the pyrolysis reactor. The problem with anoil-filled screw conveyor is, however, that the oil in the feed deviceis conveyed into the pyrolysis apparatus together with the feedmaterial. The transfer of oil can be reduced using the grooves in theinclined surface of the scraper conveyor, along which oil can flow backinto the liquid basin. There can also be, attached to the scraperconveyor of the feed device, a timer which sequentially consecutivelystarts and stops the forward movement of the conveyor, such that thechanges in the movement cause at least part of the liquid transportedwith the material to fall into the groove of the conveyor and flow backinto the liquid contained in the feed bin.

A common problem in known feed devices is also that the particles fedinto the pyrolysis apparatus must be crushed into small enough pieces.The size of the feed particles in commonly used feed devices mustusually be less than 9 mm. If overly large particles accidentally remainamong the feed particles, they can cause problems. First of all, largeparticles can block the feed device. An even greater disadvantage is,however, that the pores of the large particles retain air which containsoxygen that disrupts the production process of the pyrolysis reactorwhen it enters the reactor chamber.

In order to remove the air trapped in the particles' pores, attemptshave been made to compress the particles. Normally, the particles arecrushed as small as possible, however. Crushing the particles into smallpieces can, however, be difficult, especially when the material inquestion is rubber. In any case, crushing consumes plenty of energy,which reduces the efficiency of the whole process.

The purpose of this invention is to create a new pyrolysis feed devicethat overcomes the above-mentioned drawbacks. The pyrolysis apparatusfeed device according to the invention is characterised in what has beenpresented in the characterising section of claim 1.

According to the invention, the pyrolysis apparatus feed device includesa feed chamber equipped with closing members, through which the crushedmaterial such as plastic and/or rubber waste is conveyed into thepyrolysis chamber. According to the invention, a vacuum pump is alsolocated in conjunction with the pyrolysis apparatus's feed chamber,through which a vacuum or sufficiently large underpressure can beachieved in the feed chamber. Using the vacuum pump, air and the oxygenit contains, which is harmful to the pyrolysis process, can be removedfrom the feed chamber. At the same time as a vacuum or sufficientunderpressure is achieved in the feed chamber, also the air and theoxygen it contains can be sucked out of the pores of the particles fedinto the feed chamber. Due to the vacuum or sufficiently largeunderpressure, there is no longer oxygen in the feed chamber or theparticles inside it, or at least there is so little oxygen that it doesnot have any significance for the pyrolysis reaction. After this, thefeed chamber's closing member leading to the pyrolysis reactor is openedand the particles in the feed chamber are transferred to the pyrolysisreactor. Oxygen does not enter the pyrolysis reactor in connection withthe transfer as there is none in the feed chamber or in the pores of theparticles being transferred.

Because, as presented above, large particles of more than 9 mm can befed into the pyrolysis reactor according to the invention, the feeddevice's feed chamber and the size of its closing members can bedimensioned such that the size of the feed material does not cause anyproblems. Thus, also the channel or conveyor leading from the feedchamber to the pyrolysis reactor can be dimensioned so that largerpieces than normal can be fed through them and the material moveswithout any problems to the pyrolysis device's pyrolysis chamber. As thefeed particles do not need to be crushed as small as in known feeddevices, i.e. no more than 9 mm in size, the energy-consuming crushingphase can be entirely omitted in the pyrolysis apparatus according tothe invention.

As a vacuum or sufficient underpressure is achieved in the feed chamberaccording to the invention, also material that cannot be fed into knownfeed devices can be fed through the feed chamber into the pyrolysisreactor according to the invention. Materials such as this are floatingand porous materials. These materials cannot be fed into the feeddevices of known pyrolysis apparatuses but in a feed chamber accordingto the invention, the air and oxygen located in the pores of porousmaterials can be removed before the material is fed into the pyrolysischamber.

The feed device according to the invention can be attached to anypyrolysis apparatus, in which case the efficient feed device makes thepyrolysis apparatus even more efficient. The feed device according tothe invention can be located above the pyrolysis reactor, in which casethe feed material falls directly from the feed device into the pyrolysisapparatus's pyrolysis chamber. The feed device can, however, also bebelow the pyrolysis reactor or at its side. In this case, the advantageis that the hot pyrolysis chamber does not heat the feed device. In asolution such as this, there is a gas-tight conveyor between the feeddevice and the pyrolysis reactor, which transfers the feed material fromthe feed device to the pyrolysis reactor. When the feed device is underthe pyrolysis reactor, the hot steam from the pyrolysis chamber cannotrise into the feed device either.

According to the invention, the material to be processed in thepyrolysis apparatus, such as plastic and/or rubber waste, is fed intothe pyrolysis apparatus's pyrolysis chamber using a feed device that hasa feed opening for the material to be processed, a feed chamber, closingmembers in conjunction with the feed chamber, a vacuum pump forachieving a vacuum in the feed chamber and a discharge opening throughwhich the material to be processed can be conveyed into the pyrolysisapparatus. There can also be, in conjunction with the pyrolysisapparatus's pyrolysis chamber, a vacuum pump for achieving a vacuum orsufficient underpressure in the pyrolysis chamber.

The feed device according to the invention can be made air-tight suchthat the feed chamber closing member in conjunction with the feeddevice's feed opening has a gate valve equipped with a seal. The secondclosing member may also include a closing plate that can be pressedtightly against the end of the feed chamber. In this case, when theclosing plate of the feed device closing member is open, the feedchamber is connected to the feed device's discharge chamber. Accordingto the invention, there can be a discharge member in conjunction withthe feed device's feed chamber for transferring material from the feedchamber to the feed device's discharge chamber, from which the materialis conveyed through the discharge chamber's discharge opening into thepyrolysis apparatus's pyrolysis chamber.

The feed device of the pyrolysis apparatus can be located above thepyrolysis apparatus's pyrolysis chamber, in which case the material tobe processed can be dropped through the discharge opening into thepyrolysis chamber. When the pyrolysis apparatus's feed device is locatedbelow the pyrolysis apparatus's pyrolysis chamber or at the side of thepyrolysis chamber, a gas-tight conveyor has been attached to the feeddevice for transferring the feed material from the feed device to thepyrolysis chamber.

According to the invention, the pyrolysis apparatus has a feed devicewith which the material to be processed in the pyrolysis apparatus, suchas plastic and/or rubber waste, can be fed into the pyrolysis apparatus,in which feed device there is, for the material to be processed, a feedopening, a feed chamber, closing members in conjunction with the feedchamber and a discharge opening through which the material to beprocessed can be conveyed into the pyrolysis apparatus's pyrolysischamber.

A vacuum pump has been adjoined in conjunction with the feed device'sfeed chamber to achieve a vacuum or sufficient underpressure in the feedchamber after the material to be processed has been fed into the feedchamber and the feed chamber closing members 14, 50) have been closed.

The vacuum pump is attached to the feed chamber with a pipe which has avalve and that a vacuum of sufficient underpressure is achieved in thefeed chamber by starting up the vacuum pump and opening the valve.

A sensor or a meter has been attached in conjunction with the feedchamber in order to measure the value of the vacuum or underpressureachieved by the vacuum pump in the feed chamber.

The feed chamber's closing member in conjunction with the feed device'sfeed opening comprises a gate valve equipped with a seal and the secondclosing member of the feed chamber contains a closing plate that can bepressed tightly against the end of the feed chamber and that when thematerial to be processed has been fed into the feed chamber and both thegate valve and the closing plate are closed, a vacuum or sufficientunderpressure can be achieved in the feed chamber using the vacuum pump.

The feed chamber containing the material to be processed which has avacuum or sufficient underpressure can be opened by opening the closingplate of the feed device's closing member, in which case the feedchamber connects with the feed device's discharge chamber and furtherwith the pyrolysis apparatus's pyrolysis chamber.

A discharge member is in conjunction with the feed device's feed chamberfor transferring material from the feed chamber to the feed device'sdischarge chamber, from which the material is conveyed through thedischarge chamber's discharge opening into the pyrolysis apparatus'spyrolysis chamber.

The feed device of the pyrolysis apparatus is located above thepyrolysis apparatus's pyrolysis chamber, in which case the material tobe processed can be dropped through the discharge opening into thepyrolysis chamber.

The pyrolysis apparatus's feed device is located below the pyrolysisapparatus's pyrolysis chamber or at the side of the pyrolysis chamber,wherein a gas-tight conveyor has been attached to the feed device fortransferring the feed material from the feed device to the pyrolysischamber.

The pyrolysis apparatus feed method is a method in which the material tobe processed in the pyrolysis apparatus, such as plastic and/or rubber,is fed into the pyrolysis apparatus's feed device and onward into thepyrolysis chamber. According to the method, the material to be processedis first fed into the feed device's feed chamber, through the feedopening, after which the feed opening's closing member is closed, inwhich case both closing members of the feed chamber are closed.Thereafter, the closing member of the feed chamber's discharge openingis opened and the material to be processed is conveyed into thepyrolysis chamber.

In the pyrolysis apparatus feed method, a vacuum or sufficientunderpressure is created using the vacuum pump in the feed chamber intowhich the material to be processed has been fed and both of whoseclosing members are closed, such that air and the oxygen it contains,which is harmful to the pyrolysis process, are removed from the feedchamber and the material to be processed. After the closing member ofthe feed chamber's discharge opening has been opened, the material to beprocessed, from which the oxygen harmful to the pyrolysis process hasbeen removed, is conveyed into the pyrolysis chamber.

In the following, the invention is described using examples withreference to the appended drawings, in which

FIG. 1 shows a pyrolysis apparatus feed device according to theinvention in a material feed situation.

FIG. 2 shows the feed device with the feed chamber closed.

FIG. 3 shows the feed device with the emptying member opened.

FIG. 4 shows the feed device in a material discharge situation.

FIG. 5 shows the feed device according to the invention installed in apyrolysis apparatus above the pyrolysis chamber.

FIG. 6 shows the feed device installed in a pyrolysis apparatus underthe pyrolysis chamber.

FIG. 1 shows a pyrolysis apparatus's feed device 10 according to theinvention, which comprises a feed opening 11, closing member 14, feedchamber 20, discharge member 30, discharge chamber 40, emptying member50 and discharge opening 41. In FIG. 1, the piston 18 of the closingmember's 14 cylinder 17 has pulled the gate valve 15 to the right inFIG. 1, away from the feed opening 11, in which case the feed opening 11is open. In this case, the feed material 12 can be fed through the feedopening 11 into the feed device 10 in which the feed material 12 fallsto the bottom of the feed chamber 20. After this, the piston 18 of theclosing member's 14 cylinder 17 pushes the gate valve 15 to the left inFIG. 1, whereby the gate valve 15 closes the feed opening 11 aspresented in FIG. 2.

As presented in FIG. 2, the seal 16 of the gate valve in the feedopening 11 seals the gate valve 15 to the walls of the feed opening 11so that the feed opening 11 leading to the feed chamber 20 is closedtightly. In FIG. 2, the feed chamber 20 is in that case fully closedbecause, in addition to the feed opening 11, also the left end of thefeed chamber 20 is closed tightly with the emptying member's 50 closingplate 51, which is pressed against the end of the feed chamber 20. Toensure tightness, the closing plate 51 can be equipped with a seal.

According to the method according to the invention, when the feedchamber 20 is closed, the valve 23 of the pipe 22 leading to the vacuumpump 21 is opened in which case the vacuum pump 21 begins to suck. Thecreation of a vacuum in the feed chamber 20 is monitored using a sensor24 or meter attached to the feed chamber 20. The creation of a vacuumcan also be monitored using an automatic device.

When in the situation presented in FIG. 2, the vacuum or underpressurein the feed chamber 20 has reached the required value, the feed chamber20 is opened so that the piston 53 of the emptying member's 50 cylinder52 pulls the closing plate 51 away from the end of the feed chamber 20.

As before the opening of the closing plate 51 there is a vacuum orunderpressure in the feed chamber 20 and there can be a different typeof pressure in the discharge chamber 41 in conjunction with thepyrolysis chamber, this pressure differential can impede the opening ofthe closing plate 51. If a pressure differential such as this exists,the pressure differential can also be equalised such that, at the sametime as the closing plate 51 is opened, the piston 33 of the dischargemember's 30 cylinder 32 pushes the push plate 31 to the left in FIG. 2.

After this, the feed chamber 20 can be opened entirely so that theclosing plate 51 is moved to the position shown in FIG. 3 to the leftedge of the discharge chamber 40. In this case, the route from the feedchamber 20 to the discharge chamber 40 is open and the feed chamber 20and discharge chamber 40 are connected to each other. The dischargechamber 40 is thus also connected to the pyrolysis apparatus's pyrolysischamber.

After this, the piston 33 of the discharge member's 30 cylinder 32pushes the push plate 31 in the manner shown in FIG. 4 to the left, inwhich case the material 12 fed into the feed chamber 20 falls into thedischarge opening 41 located in the discharge chamber 40. From thedischarge opening 41, the material is dropped into the pyrolysisapparatus's pyrolysis chamber if it is located under the dischargeopening 41. If it is not possible to drop the material into thepyrolysis chamber, at least one conveyor can be located between the feeddevice and pyrolysis chamber.

When the material 12 fed into the pyrolysis apparatus's feed device 10has been transferred as presented above into the pyrolysis apparatus'spyrolysis chamber, the piston 33 of the discharge member's 30 cylinder32 pulls the push plate 31 back to the right in FIG. 4. Similarly, alsothe piston 53 of the emptying member's 50 cylinder 52 pushes the closingplate 51 against the end of the feed chamber 20, thus sealing the feedchamber 20. After this, the piston 18 of the closing member's 14cylinder 17 pulls the gate valve 15 away from the feed opening 11, inwhich case the feed opening 11 is open again as presented in FIG. 1.Thus, the feed material 12 can once again be fed through the feedopening 11 to the feed chamber 20 and the process described above beginsagain.

FIG. 5 shows the feed device 10 according to the invention installedinto the pyrolysis apparatus 60. In this case, the feed device 10 isabove the pyrolysis apparatus 60 such that the feed material fallsthrough the feed device's 10 discharge opening 41 into the pyrolysischamber 61 of the pyrolysis apparatus 60. In FIG. 5, the pyrolysisapparatus 60 is not described in more detail because the feed device 10according to the invention can be attached to all types of pyrolysisapparatuses 60.

FIG. 6 shows the feed device 10 according to the invention installed inthe pyrolysis apparatus 60 so that it is below the pyrolysis chamber 61.As the material to be fed into the pyrolysis apparatus 60 cannot bedirectly dropped into the pyrolysis chamber 61 in this solution, agas-tight conveyor 62 has been placed between the feed device 10 andpyrolysis chamber 61. The conveyor 62 lifts the material dropped ontothe conveyor through the feed device's 10 discharge opening 41 above thepyrolysis chamber 61, from where the material falls into the pyrolysischamber 61 through the pipe 63.

LIST OF REFERENCE NUMBERS

-   10 Feed device-   11 Feed opening-   12 Feed material-   14 Closing member-   15 Gate valve-   16 Gate valve seal-   17 Cylinder-   18 Piston-   20 Feed chamber-   21 Vacuum pump-   22 Pipe-   23 Valve-   24 Sensor-   30 Discharge member-   31 Push plate-   32 Cylinder-   33 Piston-   40 Discharge chamber-   41 Discharge opening-   50 Emptying member-   51 Closing plate-   52 Cylinder-   53 Piston-   60 Pyrolysis apparatus-   61 Pyrolysis chamber-   62 Conveyor-   63 Pipe

1. A feed device of a pyrolysis apparatus, through which material to beprocessed in the pyrolysis apparatus, such as plastic and/or rubberwaste, can be fed into the pyrolysis apparatus, in which feed devicethere is a feed opening for the material to be processed, a feedchamber, closing members in conjunction with the feed chamber and adischarge opening, through which the material to be processed can beconveyed to a pyrolysis chamber of the pyrolysis apparatus wherein avacuum pump has been attached in conjunction with the feed device's feedchamber in order to achieve a vacuum or sufficient underpressure in thefeed chamber after the material to be processed has been fed into thefeed chamber and the feed chamber's closing members have been closed. 2.The feed device according to claim 1, wherein the vacuum pump isattached to the feed chamber with a pipe which has a valve and a vacuumor sufficient underpressure is achieved in the feed chamber by startingup the vacuum pump and opening the valve.
 3. The feed device accordingto claim 1, wherein a sensor or meter has been attached in conjunctionwith the feed chamber in order to measure the value of the vacuum orunderpressure that the vacuum pump has created in the feed chamber. 4.The feed device according to claim 1, wherein one closing member of thefeed chamber's in conjunction with the feed device's feed openingcomprises a gate valve equipped with a seal and the second closingmember of the feed chamber contains a closing plate that can be pressedtightly against the end of the feed chamber and when the material to beprocessed has been fed into the feed chamber and both the gate valve andthe closing plate are closed, a vacuum or sufficient underpressure canbe achieved in the feed chamber using the vacuum pump.
 5. The feeddevice according to claim 4, wherein the feed chamber containing thematerial to be processed which has a vacuum or sufficient underpressurecan be opened by opening the closing plate of the feed device's closingmember, in which case the feed chamber is connected with the feeddevice's discharge chamber and further with the pyrolysis chamber of thepyrolysis apparatus.
 6. The feed device according to claim 1, whereinthere is a discharge member in conjunction with the feed device's feedchamber for transfer of material from the feed chamber to the dischargechamber of the feed device, from where the material is conveyed throughthe discharge chamber's discharge opening into the pyrolysis chamber ofthe pyrolysis apparatus.
 7. The feed device according to claim 6,wherein the feed device of the pyrolysis apparatus is located above thepyrolysis apparatus's pyrolysis chamber in which case the material to beprocessed can be dropped through the discharge opening into thepyrolysis chamber.
 8. The feed device according to claim 1, wherein thefeed device of the pyrolysis apparatus is located under the pyrolysischamber of the pyrolysis apparatus or at side of the pyrolysis chamber,in which case a gas-tight conveyor has also been attached to the feeddevice for transporting the feed material from the feed device to thepyrolysis chamber.
 9. A feed method for feeding material to be processedin a pyrolysis apparatus, such as plastic and/or rubber waste, into afeed device of the pyrolysis apparatus and onward into the pyrolysischamber, the method comprising the steps of: feeding the material to beprocessed into the feed device's feed chamber, through a feed openingclosing a closing member of the feed opening whereby both closingmembers of the feed chamber are closed; opening the closing member ofthe feed chamber's discharge opening and conveying the material (12) tobe processed into the pyrolysis chamber (61); wherein a vacuum orsufficient underpressure is achieved using the vacuum pump in the feedchamber into which the material to be processed has been fed and both ofwhose closing members are closed, such that air and the oxygen itcontains, which is harmful to the pyrolysis process, are removed fromthe feed chamber and from the material to be processed; after which,when the closing member of the feed chamber's discharge opening has beenopened, the material to be processed, from which the oxygen harmful tothe pyrolysis process has been removed, is conveyed into the pyrolysischamber.